Effectiveness of cyclic treatment of municipal wastewater by Tetradesmus obliquus - Loofah biofilm, its internal community changes and potential for resource utilization.

Microalgae biofilm has garnered significant attention from researchers in the field of sewage treatment due to its advantages such as ease of collection and stable sewage treatment capabilities. Using agricultural waste as biofilm carriers has become a hotspot in reducing costs for this method. This study first combined Tetradesmus obliquus with loofah to form a microalgae biofilm for the study of periodic nitrogen and phosphorus removal from municipal wastewater. The biofilm could stably treat 7 batches of wastewater within one month. The removal rate of TP almost reached 100 %, while the removal rates of NH4 + and TN both reached or exceeded 80 %. The average biomass yield over 25 days was 102.04 mg/L/day. The polysaccharide content increased from 8.61 % to 16.98 % during the cyclic cultivation. The lipid content gradually decreased from 40.91 to 26.1 %. The protein content increased from 32.93 % in the initial stage to 41.18 % and then decreased to 36.31 % in the later stage. During the mid-stage of culturing, the richness of anaerobic bacteria decreased, while the richness of aerobic and facultative bacteria increased, which was conducive to the construction of the microalgae-bacteria symbiotic system and steadily improved the effect of nitrogen and phosphorus removal. As the culturing progressed, the Rotifers that emerged during the mid-stage gradually damaged the biofilm over time, leading to a decline in the effectiveness of sewage treatment in the later stages. This study offers technical support for carrier selection in microalgae biofilm methods and for the periodic removal of nitrogen and phosphorus from wastewater.

Repurposing Cotton Gin Trash for Cellulose Nanofibril-Silver Hybrid and Ultralight Silver-Infused Aerogel.

Cellulose nanofibril-silver (CNF-Ag) hybrid and ultralight silver-infused aerogel were produced using cotton gin trash (CGT), an abundant agro-waste material. This repurposing of CGT was achieved by exploiting its potential for CNF extraction and the in situ synthesis of silver nanoparticles (Ag NPs). CNFs were extracted from CGT through a mechanical shearing process. These CNFs served as a multifunctional nanotemplate for the controlled reduction of Ag ions, efficient nucleation, and stabilization of NPs, resulting in the production of a high concentration of Ag NPs (ca. 19 wt %) within the CNFs. Transmission electron microscopy images of cross-sectioned CNFs confirmed the uniform dispersion of NPs (ca. 18 nm diameter) inside the CNFs. Rietveld refinement analysis of X-ray diffraction patterns revealed that CNFs produced smaller Ag crystallites compared to CGT microparticles. The CNF-Ag hybrid was then fabricated into an aerogel using freeze-drying, with its weight being light enough to rest on a cotton flower's stamen. The infusion of Ag NPs led to approximately 20% reductions in the specific surface area and pore volume of the aerogel.

Furfural as a low-volume, high-value asset from agricultural residues: A review on production, agricultural applications and environmental sustainability.

This comprehensive review explores furfural production from agricultural residues, focusing on its significance as a low-volume, high-value asset crucial for environmental sustainability. It covers diverse production technologies, recent advancements, and applications in agriculture, evaluating furfural's potential to enhance crop resilience and yield. Showing its role in a circular economy, the review discusses how furfural can replace conventional petrochemical processes, thereby reducing environmental impact. Case studies, such as successful implementations with cotton biomass byproducts, illustrate furfural's practical applications and environmental benefits. The study underscores the need for ongoing research, supportive policies, and furfural's growing role in sustainable agriculture and industry. It is focused on furfural's essential contribution to promoting environmental stewardship and sustainable practices. By examining furfural's role as a value-added product from agricultural residues, this review provides insights into its economic viability and potential challenges.

Blends of Carboxymethyl Cellulose and Cottonseed Protein as Biodegradable Films.

With the increasing awareness of plastic pollution in the environment and the accumulation of microplastics in water, a significant amount of research and development is ongoing to replace the synthetic plastics in packaging and coatings. In this work, we explored the blends of carboxymethyl cellulose (CMC) and washed cottonseed meal (CSM, consisting mostly of cottonseed protein) as agro-based, biodegradable, and sustainable alternatives to plastics. Glycerol was found to be a suitable plasticizer for these blends. The blends of CMC/CSM were produced as single-layer films from 50 to 90 µm in thickness, consisting of different proportions of the components and plasticizer. The evaluated properties included opacity, water vapor permeability, mechanical properties, thermogravimetric analysis, moisture sorption analysis, and water swelling test. Higher percentages of CSM in the blend resulted in higher opacity and lower water vapor permeation rates. The mechanical strength waned with lower levels of CMC. Possible applications for these blends include their use as water-soluble food packaging and coatings and as dissolvable bags and pouches for detergents and agrochemicals.

Microalgae as future food: Rich nutrients, safety, production costs and environmental effects.

The improvement of food security and nutrition has attracted wide attention, and microalgae as the most promising food source are being further explored. This paper comprehensively introduces basic and functional nutrients rich in microalgae by elaborated tables incorporating a wide variety of studies and summarizes factors influencing their accumulation effects. Subsequently, multiple comparisons of nutrients were conducted, indicating that microalgae have a high protein content. Moreover, controllable production costs and environmental friendliness prompt microalgae into the list that contains more promising and reliable future food. However, microalgae and -based foods approved and sold are limited strictly, showing that safety is a key factor affecting dietary consideration. Notably, sensory profiles and ingredient clarity play an important role in improving the acceptance of microalgae-based foods. Finally, based on the bottleneck in the microalgae food industry, suggestions for its future development were discussed.

Soil Biodegradation Resistance of Cotton Fiber Doped with Interior and Exterior Silver Nanoparticles.

Engineering fibers with nanomaterials is an effective way to modify their properties and responses to external stimuli. In this study, we doped cotton fibers with silver nanoparticles, both on the surface (126 ± 17 nm) and throughout the fiber cross section (18 ± 4 nm), and examined the resistance to soil biodegradation. A reagent-free one-pot treatment of a raw cotton fabric, where noncellulosic constituents of the raw cotton fiber and starch sizing served as reducing agents, produced silver nanoparticles with a total concentration of 11 g/kg. In a soil burial study spanning 16 weeks, untreated cotton underwent a sequential degradation process-fibrillation, fractionation, and merging-corresponding to the length of the soil burial period, whereas treated cotton did not exhibit significant degradation. The remarkable biodegradation resistance of the treated cotton was attributed to the antimicrobial properties of silver nanoparticles, as demonstrated through a test involving the soil-borne fungus Aspergillus flavus. The nonlinear loss behavior of silver from the treated cotton suggests that nanoparticle depletion in the soil depends on their location, with interior nanoparticles proving durable against environmental exposure.

Fractionation and Lability of Phosphorus Species in Cottonseed Meal-Derived Biochars as Influenced by Pyrolysis Temperature.

Defatted cottonseed meal (CSM), the residue of cottonseeds after oil extraction, is a major byproduct of the cotton industry. Converting CSM to biochar and utilizing the goods in agricultural and environmental applications may be a value-added, sustainable approach to recycling this byproduct. In this study, raw CSM was transformed into biochar via complete batch slow pyrolysis at 300, 350, 400, 450, 500, 550, and 600 °C. Thermochemical transformation of phosphorus (P) in CSM during pyrolysis was explored. Fractionation, lability, and potential bioavailability of total P (TP) in CSM-derived biochars were evaluated using sequential and batch chemical extraction techniques. The recovery of feed P in biochar was nearly 100% at ≤550 °C and was reduced to <88% at 600 °C. During pyrolysis, the organic P (OP) molecules predominant in CSM were transformed into inorganic P (IP) forms, first to polyphosphates and subsequently to orthophosphates as promoted by a higher pyrolysis temperature. Conversion to biochar greatly reduced the mobility, lability, and bioavailability of TP in CSM. The biochar TP consisted of 9.3-17.9% of readily labile (water-extractable) P, 10.3-24.1% of generally labile (sequentially NaHCO3-extractable) P, 0.5-2.8% of moderately labile (sequentially NaOH-extractable) P, 17.0-53.8% of low labile (sequentially HCl-extractable) P, and 17.8-47.5% of residual (unextractable) P. Mehlich-3 and 1 M HCl were effective batch extraction reagents for estimating the "readily to mid-term" available and the "overall" available P pools of CSM-derived biochars, respectively. The biochar generated at 450 °C exhibited the lowest proportions of readily labile P and residual P compounds, suggesting 450 °C as the optimal pyrolysis temperature to convert CSM to biochar with maximal P bioavailability and minimal runoff risk.

The Effects of Oil Content on the Structural and Textural Properties of Cottonseed Butter/Spread Products.

Plant-based butters from nuts and seeds have steadily increased in consumer popularity due to their unique flavors and healthy nutritional properties. Oil content is a critical parameter to measure the proper consistency and stability of plant butter and spread products. Previous work has shown that glandless cottonseed can be used to formulate cottonseed butter products to increase the values of cottonseed. As part of the efforts made in the valorization of cottonseed, this work evaluated the effects of oil content on the microstructural and textural properties of cottonseed butter/spread products. While the oil content in the raw cottonseed kernels was 35% of the kernel biomass, additional cottonseed oil was added to make cottonseed butter products with six oil content levels (i.e., 36, 43, 47, 50, 53, and 57%). The values of three textural parameters, firmness, spreadability, and adhesiveness, decreased rapidly in an exponential mode with the increasing oil content. The particle size population in these butter samples was characterized by similar trimodal distribution, with the majority in the middle mode region with particle sizes around 4.5-10 µm. Higher oil content decreased the butter particle size slightly but increased oil separation during storage. The oxidation stability with a rapid oxygen measurement was gradually reduced from 250 min with 36% oil to 65 min with 57% oil. The results of this work provide information for the further optimization of formulation parameters of cottonseed butter products.

Unveiling the Hidden Value of Cotton Gin Waste: Natural Synthesis and Hosting of Silver Nanoparticles.

Cotton gin waste presents a significant challenge in the cotton ginning industry due to its abundant generation and limited disposal options. In this study, we explored the potential of cotton gin waste as a naturally occurring source material that can synthesize and host silver nanoparticles. The noncellulosic constituents of cotton gin waste served as effective reducing agents, facilitating the conversion of silver ions into silver atoms, while its porous structure acted as a microreactor, enabling controlled particle growth. A simple heat treatment of cotton gin waste powder in an aqueous silver precursor solution actualized the in situ synthesis of silver nanoparticles, without the need for additional chemical agents. Remarkably, a high concentration of silver nanoparticles (14.7%) with an average diameter of approximately 27 nm was produced throughout the entire volume of cotton gin waste. Electron microscopic images of cross-sectioned cotton gin waste confirm the internal formation of nanoparticles. Rietveld refinement analysis of X-ray diffraction patterns showed that the majority of the nanoparticles possess a cubic silver crystal structure. By leveraging the well-known biocidal properties of silver nanoparticles, the resulting silver nanoparticle-filled cotton gin waste holds promise for novel antimicrobial and antifungal material applications.

Characterization of the Nonpolar and Polar Extractable Components of Glanded Cottonseed for Its Valorization.

Cottonseed is the second major product of cotton (Gossypium spp.) crops after fiber. Thus, the characterization and valorization of cottonseed are important parts of cotton utilization research. In this work, the nonpolar and polar fractions of glanded (Gd) cottonseed were sequentially extracted by 100% hexane and 80% ethanol aqueous solutions and subjected to 13C and 1H nuclear magnetic resonance (NMR) spectroscopy and Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS), respectively. The nonpolar (crude oil) extracts showed the characteristic NMR peak features of edible plant oils with the absence of ω-3 linolenic acid. Quantitative analysis revealed the percentage of polyunsaturated, monounsaturated, and saturated fatty acids as 48.7%, 16.9%, and 34.4%, respectively. Both general unsaturated fatty acid features and some specific olefinic compounds (e.g., oleic, linolenic, and gondonic acids) were found in the nonpolar fraction. In the polar extracts, FT-ICR MS detected 1673 formulas, with approximately 1/3 being potential phenolic compounds. Both the total and phenolic formulas fell mainly in the categories of lipid, peptide-like, carbohydrate, and lignin. A literature search and comparison further identifies some of these formulas as potential bioactive compounds. For example, one compound [2,5-dihydroxy-N'-(2,3,4-trihydroxybenzylidene) benzohydrazide] identified in the polar extracts is likely responsible for the anticancer function observed when used on human breast cancer cell lines. The chemical profile of the polar extracts provides a formulary for the exploration of bioactive component candidates derived from cottonseed for nutritive, health, and medical applications.

Multiple spectral comparison of dissolved organic matter in the drainage basin of a reservoir in Northeast China: Implication for the interaction among organic matter, iron, and phosphorus.

Dissolved organic matter (DOM) plays a major role in ecological systems, affecting the fate and transportation of iron (Fe) and phosphorus (P). To better understand the geochemical cycling of these components, soil and sediment samples were collected around a reservoir downstream of a typical temperate forest in Northeast China. The DOM fractions from these soils, river, and reservoir sediments were extracted and then characterized by spectroscopic techniques. Comparative characterization data showed that the DOM pool of the Xishan Reservoir was partly autochthonous and derived from runoff and deposition of material in terrestrial ecosystems upstream. The upper reaches of the reservoir had significantly lower total Fe (TFe) content in the DOM extracts than those found in the reservoir (p < 0.05). Within the DOM, TFe was correlated with the amino acid tryptophan (p < 0.01). There was also a strong positive correlation between total P (TP) concentrations in DOM and tyrosine (p < 0.01). Organic P (Po) comprised most of the DOM TP, and was related to dissolved organic carbon (DOC) content and the amino acid tyrosine (p < 0.01). The interaction among DOM, Fe, and P appears to be due to complexation with tryptophan (Fe) and tyrosine (P). This suggests that the formation of Fe-DOM-P would be produced more readily than DOM-Fe-P complexes under optimal conditions. The interaction among DOM, Fe, and P can promote the coordinated migration, transformation, and ultimate fate of components that are complex with DOM from riverine and reservoir ecosystems, ultimately leading to accumulation within a reservoir and transport to downstream regions when reservoir dams are released. Reservoir dams can effectively intercept DOM and minerals prevent its flow downstream; however, it is important to understand the co-cycling of DOM, Fe and P within reservoirs, downstream rivers, and ultimately oceans. The involvement of amino acid components of DOM, tyrosine and tryptophan, in DOM complexation is an issue that requires further study.

Bilayer Films of Poly(lactic acid) and Cottonseed Protein for Packaging Applications.

Poly(lactic acid) (PLA) is a common biobased film-former made from renewable biomass, such as polysaccharides from sugarcane, corn, or cassava. It has good physical properties but is relatively expensive when compared to the plastics used for food packaging. In this work, bilayer films were designed, incorporating a PLA layer and a layer of washed cottonseed meal (CSM), an inexpensive agro-based raw material from cotton manufacturing, where the main component is cottonseed protein. These bilayer films were made through the solvent casting method. The combined thickness of the PLA/CSM bilayer film was between 47 and 83 µm. The thickness of the PLA layer in this film was 10%, 30%, or 50% of the total bilayer film's thickness. Mechanical properties of the films, opacity, water vapor permeation, and thermal properties were evaluated. Since PLA and CSM are both agro-based, sustainable, and biodegradable, the bilayer film may be used as an eco-friendlier food packaging material, which helps reduce the environmental problems of plastic waste and microplastics. Moreover, the utilization of cottonseed meal may add value to this cotton byproduct and provide a potential economic benefit to cotton farmers.

Cross-Serological Reaction of Glandless Cottonseed Proteins to Peanut and Tree Nut Allergic IgE.

Food allergy is a potentially life-threatening health concern caused by immunoglobulin E (IgE) antibodies that mistakenly recognize normally harmless food proteins as threats. Peanuts and tree nuts contain several seed storage proteins that commonly act as allergens. Glandless cottonseed, lacking the toxic compound gossypol, is a new food source. However, the seed storage proteins in cottonseed may act as allergens. To assess this risk, glandless cottonseed protein extracts were evaluated for IgE binding by peanut and tree nut allergic volunteers. ELISA demonstrated that 25% of 32 samples had significant binding to cottonseed extracts. Immunoblot analysis with pooled sera indicated that IgE recognized a pair of bands migrating at approximately 50 kDa. Excision of these bands and subsequent mass-spectrometric analysis demonstrated peptide matches to cotton C72 and GC72 vicilin and legumin A and B proteins. Further, in silico analysis indicated similarity of the cotton vicilin and legumin proteins to peanut vicilin (Ara h 1) and cashew nut legumin (Ana o 2) IgE-binding epitopes among others. The observations suggest both the cotton vicilin and legumin proteins were recognized by the nut allergic IgE, and they should be considered for future allergen risk assessments evaluating glandless cottonseed protein products.

Oxidative Stability of Cottonseed Butter Products under Accelerated Storage Conditions.

Cottonseed is a natural product of cotton (Gossypium spp.) crops. This work evaluated the oxidative stability of cottonseed butters through accelerated autoxidation by storage at 60 °C for 25 days. Three oxidative stability parameter values (peroxide value, p-anisidine value, and total oxidation value) were monitored over the storage time. These chemical measurements revealed that the storage stability of the butter products was dominated by primary oxidation of lipid (oil) components, while the secondary oxidation levels were relatively unchanged over the storage time. An analysis of the tocopherols (natural oxidants in cottonseed) suggested not only the protection function of the molecules against oxidation of the cottonseed butter during storage, but also the dynamic mechanism against the primary oxidation of lipid components. Attenuated total reflectance-Fourier-transform infrared spectroscopy (ATR-FTIR) data confirmed no changes in the major C functional groups of cottonseed butters over the storage time. On the other hand, characteristic minor peaks of conjugated dienes and trienes related to lipid oxidation were impacted by the accelerated storage. As each day of accelerated oxidation at 60 °C is equivalent to 16 days of storage at 20 °C, observations in this work should have reflected the oxidative stability behaviors of the cottonseed butters after about 13 months of shelf storage under ambient storage conditions. Thus, these data that were collected under the accelerated oxidation testing would be useful not only to create a better understanding of the autooxidation mechanism of lipid molecules in cottonseed butters, but also in developing or recommending appropriate storage conditions for cottonseed end products to prevent them from quality degradation.

Washable Antimicrobial Wipes Fabricated from a Blend of Nanocomposite Raw Cotton Fiber.

In this study, a simple and effective way to produce washable antimicrobial wipes was developed based on the unique ability of raw cotton fiber to produce silver nanoparticles. A nanocomposite substructure of silver nanoparticles (25 ± 3 nm) was generated in raw cotton fiber without reducing and stabilizing agents. This nanocomposite raw cotton fiber (2100 ± 58 mg/kg in the concentration of silver) was blended in the fabrication of nonwoven wipes. Blending small amounts in the wipes-0.5% for antimicrobial properties and 1% for wipe efficacy-reduced the viability of S. aureus and P. aeruginosa by 99.9%. The wipes, fabricated from a blend of 2% nanocomposite raw cotton fiber, maintained their antibacterial activities after 30 simulated laundering cycles. The washed wipes exhibited bacterial reductions greater than 98% for both Gram-positive and Gram-negative bacteria.

Initial Formulation of Novel Peanut Butter-like Products from Glandless Cottonseed.

Glandless (Gl) cottonseed is a unique cotton variety with only a trace content of toxic gossypol present. This new cottonseed raises the potential of its enhanced utilization as an agro-food for human consumption. In this work, Gl cottonseed kernels were used with additional cottonseed oil to produce novel peanut butter-like products. Kernels roasted at two temperatures (140 or 150 °C) for a given time (15 or 30 min) were first ground with different ratios of cottonseed oil and two other ingredients (i.e., salt and sugar) with a food blender, and then passed through a meat grinder with a 4-mm-hole grinding plate. Per the preliminary result, the butter-like products with Gl kernels roasted at 150 °C were subject to further structural and textural evaluation. The color of the two butter-like products was comparable to a commercial peanut butter, but the formers' textural properties were significantly different (p ≤ 0.05) from the latter. Morphologic examination by Scanning Electron Microscopy (SEM) and cryo-SEM revealed that the butter product with a longer (30 min) roasting time possessed a smoother surface than the products with a shorter (15 min) roasting time. Oil stability test showed no substantial oil separation (<3%) from the butter products over 7 weeks at ambient temperature (22 °C). This work provides the basic information and parameters for lab cottonseed butter making so that optimization and characterization of cottonseed butter formation can be designed and performed in future research.

Molecular level characterization of the effect of roasting on the extractable components of glandless cottonseed by Fourier transform ion cyclotron resonance mass spectrometry.

Roasting is a technological process in some food applications of agricultural products. To investigate the composition changes of the extractable functional/bioactive components of cottonseed, in this work, glandless cottonseed kernels were roasted at 110, 120, 140 and 150 °C for 15 min, respectively. The UV/vis data of the 80 % ethanol extracts found that roasting increased the level of phenolic compounds. Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry of the extracts identified about 44 % to 55 % of total formulas as potential phenolic compounds. Roasting (up to 140 °C) mainly increased carbohydrate-, lignin-, and tannin-like compounds while lipid-like compounds decreased. The compositional changes at 150 °C were less than those at 140 °C, attributed to devolatilization at the higher temperature. The information of chemical profiling of cottonseed and the roasting impact would be greatly useful in enhanced utilization of cottonseed as nutrient and functional foods or food supplements.

Self-induced transformation of raw cotton to a nanostructured primary cell wall for a renewable antimicrobial surface.

Herein, raw cotton is shown to undergo self-induced transformation into a nanostructured primary cell wall. This process generates a metal nanoparticle-mediated antimicrobial surface that is regenerable through multiple washings. Raw cotton, without being scoured and bleached, contains noncellulosic constituents including pectin, sugars, and hemicellulose in its primary cell wall. These noncellulosic components provide definitive active binding sites for the in situ synthesis of silver nanoparticles (Ag NPs). Facile heating in an aqueous solution of AgNO3 activated raw cotton to produce Ag NPs (ca. 28 nm in diameter and 2261 mg kg-1 in concentration). Compared with scoured and bleached cotton, raw cotton requires lower concentrations of AgNO3-ten times lower for Klebsiella pneumonia and two times lower for Staphylococcus aureus-to achieve 99.9% reductions of both Gram-positive and Gram-negative bacteria. The Ag NPs embedded in the primary cell wall, which was confirmed via transmission electron microscopy images of the fiber cross-sections, are immobilized, exhibiting resistance to leaching as judged by continuous laundering. A remarkable percentage (74%) of the total Ag NPs remained in the raw cotton after 50 laundering cycles.

Thermosensitive textiles made from silver nanoparticle-filled brown cotton fibers.

Filling fibers with nanomaterials can create new functions or modify the existing properties. However, as nanocomposite formation for natural cellulosic fibers has been challenging, little information is available on how the embedded nanomaterials alter the properties of cellulosic fibers. Here we filled brown cotton fibers with silver nanoparticles (Ag NPs) to examine their thermosensitive properties. Using naturally present tannins in brown cotton fibers as a reducing agent, Ag NP-filled brown cotton fibers (nanoparticle diameter of about 28 nm, weight fraction of 12 500 mg kg-1) were produced through a one-step process without using any external agents. The in situ formation of Ag NPs was uniform across the nonwoven cotton fabric and was concentrated in the lumen of the fibers. The insertion of Ag NPs into the fibers shifted the thermal decomposition of cellulose to lower temperatures with increased activation energy and promoted heat release during combustion. Ag NPs lowered the thermal effusivity of the fabric, causing the fabric to feel warmer than the control brown cotton. Ag NP-filled brown cotton was more effectively heated to higher temperatures than control brown cotton under the same heating treatments.

Enhancing harvest of biodiesel-promising microalgae using Daphnia domesticated by amino acids.

Mass production of microalgal biodiesel is hindered by microalgae harvesting efficiency and costs. In this study, Daphnia domesticated by amino acids were used to harvest microalgae via ingesting. The main factors (density of Daphnia, salinity, pH, light-environment, temperature and algal concentration) that were conducive to Daphnia feeding were optimized. Under the optimal condition, Microalgae-feeding Daphnia were domesticated by adding D-glutamic acid and L-cysteine as stimulating factors. After that, the ingestion rate of domesticated Daphnia increased by 24.93%. The presence of Daphnia as a predator can induce microalgae to mass into clusters. Combining Daphnia feeding and the inductive defense flocculation of microalgae, the harvesting rate of mixed algae (Chlorella pyrenoidosa and Scenedesmus obliquus) reached over 95% after 9 h. Overall, this work suggested that Daphnia feeding process is a green and economical approach for microalgae harvesting.